Machsupport Forum
General CNC Chat => Show"N"Tell ( Your Machines) => Topic started by: zarzul on May 14, 2009, 03:47:42 PM
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Just thought I would share my lathe conversion in progress.
It is a harbor freight 13 x 40.
I am going to use a servo on the Z axis and a 1200oz stepper on the X.
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Looking good Zarzul.....REAL good.
I may do my Clausing in a similar fasion soon.
Where did you get the red bellows ?
Are they intended for this application ?
I've seen some folks use motorcycle fork/shock covers.
Thanks,
RC
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Your Z axis Lead screw must cost a fortune, really nice lathe, looking for more pics.
Thanks to share.
Jeff
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Yep, motorcycle fork covers, I guess the red was a dead giveaway.
Got the leadscrew on ebay for $79, it is very nice, brand new, 4 circuit ballscrew. It's original cost is probably many many times more that my whole lathe.
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They should hold up well. Really took a beating on my bike...when I used to ride.
Anxious to see your X motor mounting configuration.
Keep us posted.
Thanks again,
RC
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Looking good. :)
Brett
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Nice looking indeed! And you got ground ballscrews - perfect! $79 for that ballscrew... wow... I wish I knew where to look for these ;)
You have only one screw holding the X ball nut? With such ballscrews I wouldn't compromise on that ;)
Daniel
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Very neat job Arnie :)
Hood
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Hi, Zarzul, keep posting with new pics, I have a 11 X 23 Grizzly lathe I would like to upgrade with CNC controller, so keep posting please.
Jeff
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zarzul,
Very nice conversion; I would like to convert an old craftsman metal lathe,
looks like more skills required than I've mastered though! Please keep on w/ the
photos...Great thread.
Glenn
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Well I finished up enough to start making chips.
I still have the speed pickup to install, start forward & reverse relay and limitswitches to do, and a cover for the Z axis pulley.
The axis are both very fast, I haven't gotten the guts to run them as fast as they will go. I slowed the X down to 50"/min and the Z down to 100"/min.
Can't detect any backlash in the X, the Z has 3 mils, but it is all in the mounting block for the thrust bearing, I think I need to pin it with a dowel.
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Looks real nice. If you had it to do over again, what would you do differently?
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Ahh......now you can make chips. Isn't it a nice feeling. Hopefully all will work to your expectations.
I have a few things to do on my conversion but have been testing it out and making chips.
Must be nice to have some space in the machine to mount the screws. I like the shock covers.
RICH
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I have had a chance to use it a little more and it seems to be working out real well.
Still need to get the speed pickup, limits and start/stop controls.
Not sure if I can think of much to do differently, maybe make the guard cover for the X axis smaller.
The Z axis screw is very nice, extremely accurate, probably a little overkill but it fit just fine.
The X axis screw is pretty small but had to be in order to get it into such a small space.
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Looks real good Arnie............... so your makeing chips. Show us your bits!!!! ;D
Brett
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Hey Zarzul,
How about joining in on some thread testing?
Give her a test or two!
RICH
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Right after I get a speed pickup made.
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As long as you have a rack in the back window for the 12 GA sawed off shotgun.
Like they used to say in the boonies of Tennessee, "She's sittin there in case you need to shed some daylight"
but in the mean time "Think I 'll just watch the nail in the tree rust some". ;)
RICH
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Zarzul:
I am about to purchase the motors for my 12X36 lathe conversion and was wanting to know about the motor sizes you chose and the pulley ratio. It sounds like they have the speed that you need.
The Z axis stepper looks like about a NEMA 23 stepper with 600 oz/in torque and a 3 to 1 pulley ratio?
The X axis looks like a NEMA 34 with 600 oz/in torque with a 2 to 1 pulley ratio?
Bill
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Bill,
The Z axis is a servo motor, Kollomorgen, with about 3 to 1 reduction driving a 3tpi ballscrew. The X axis is a 1125oz/in nema 34 with a 2/1 ratio, driving a 5tpi ballscrew. I was a little worried about the reduction on the servo but it drives it just fine, great resolution and speed much faster than I would allow. The X axis has good resolution also, not as fine as the servo, but very good, I use a 1/8 microstepping controller.
The speed of the stepper is not nearly as fast as the servo but more than fast enough for good rapids.
Arnie
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I did get a speed pickup mounted and have been doing some threading, seems to work just fine although I am using an older version. .034 or something like that.
Also just finished installing a VFD, my Harbor Freight motor died, bad starting cap. I had more trouble troubleshooting it to the cap than it took me to swap to a 3phase motor and vfd.
I went through the relay starter with a fine tooth comb until I discovered the leaking cap, had that thing apart 6 times before the light came on. Half the wires in the relay start/reverse were poorly connected, half loose, the relays were designed for larger wire and would not crimp down tight on the small guage wire they used. That lead me down the path to thinking loose wiring.
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Thanks for the response.
I have a smaller lathe that I use for manual work and the start capacitor went out on it (distinct buzzing or humming sound), ordered that and replaced. A month later the run capacitor went out. Funny thing when a run capacitor goes out, the motor continues to run (however badly) and the motor gets extremely hot until the electrolyte melts out of the run capacitor and smokes up the whole place.
Needless to say, I have half a dozen of each capacitor as spares now!
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Now you have spares it will never, ever happen again :D
Tweakie.
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More pics please! As I have the same lathe and would like to do the same mod. Also drug a bridgeport series II down from riverton, wyo. just a bit ago. It was a real adventure. Crossing South Pass was surreal.
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Nice work ZarZ, I have an HF 12x36 lathe and I gotta say it looks nearly identical to that machine. I have often considered converting it and the way you did that machine is so damn simple it is not funny. I was not aware you can remove the front of the apron like that.. It just seems like it makes mounting a ballscrew mount a piece of cake. Did you actually just use the existing bolt holes that used to hold the apron on to affix it? The nice thing is that the old drive screws are now gone and ya just got that one screw going thru there... I wonder if a nice sheetmetal cover over that screw would work somehow.. Is that a 1" screw or maybe 3/4 inch diameter? I have some DC servos here that I need to put some encoders on and I could be running pretty easy... Gotta see what I can come up with. Got any pics of stuff you have made with this machine? I have had this lathe for many years now and it has been very accurate for the price point... peace
Pete
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Pete,
Yes the 12x36 is almost a twin of the 13x40. I ended up using motorcycle fork boots for my ballscrew cover, the screw is almost 1 1/2", I got a unbelievable deal on ebay for it. I had to sacrafice a few inches of stroke but it was worth it. I haven't made a lot of big projects with it, mainly parts of other projects, mostly milling stuff, I did bore and thread an AR15 upper receiver. It just love the ease of threading, any pitch, right up close to a shoulder you name it, it is a breeze.
Yes I use the existing bolt holes for the apron.
You should dive in on your conversion, once you get done you will wish you had done it years ago.
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Zarz,
Thanks for the info man, that is one huge badass leadscrew ya got there... I would think a 3/4 inch screw would be more than adequate... What is your spindle indexing setup? Got any pictures? Are you gonna rig up some gang tooling for that bad boy? Did you make the AR receiver? Ya got me thinking here now man... nice work.. peace
Pete